This article presents a power management unit (PMU) enabling ultra-wide power-performance tradeoff well beyond voltage scaling, and adaptation to the sensed power/energy availability in the harvester and battery. Gap-less power scaling by more than five orders of magnitude and down to nW permits continuous microcontroller unit (MCU) operation regardless of the battery energy availability, thanks to a sub-mm2 on-chip harvester. Such battery-indifferent operation allows to considerably shrink the battery down, as battery discharge no longer has disruptive impact on operation. Battery-indifferent operation is enabled by introducing a purely harvested power mode in the PMU, and widely power-scalable circuits in critical blocks to maintain the power efficiency nearly constant down to nW level. To avoid pessimistic power/timing overdesign, a novel self-biasing comparator and a zero current switching scheme with fast convergence and circuit sharing across power modes are proposed. A 180-nm testchip shows MSP430-like MCU power scaling from sub-mW down to 1.85 nW, with at least 27 $\times $ power dynamic range extension compared to prior art. Self-start-up from 2-nW harvested power is demonstrated, corresponding to a 0.8-mm2 on-chip solar cell with 100-lx illuminance (i.e., equivalent to a very dark overcast day).

中文翻译：

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用于电池无关系统的集成电源管理，具有低至 nW 的超宽适应

本文介绍了一种电源管理单元 (PMU)，它能够实现远远超出电压缩放的超宽功率性能折衷，并适应采集器和电池中检测到的功率/能量可用性。得益于亚平方毫米的片上采集器，无间隙功率缩放超过五个数量级并降至 nW，允许微控制器单元 (MCU) 连续运行，无论电池能量是否可用。这种与电池无关的操作允许大大缩小电池容量，因为电池放电不再对操作产生破坏性影响。通过在 PMU 中引入纯收集功率模式，以及在关键模块中广泛功率可扩展的电路，以保持低至 nW 级的功率效率几乎恒定，从而实现电池无关操作。为避免悲观的功率/时序过度设计，提出了一种新颖的自偏置比较器和一种具有快速收敛和跨电源模式电路共享的零电流开关方案。一个 180 纳米的测试芯片显示，与现有技术相比，类似 MSP430 的 MCU 功率从 sub-mW 降低到 1.85 nW，功率动态范围至少扩展了 27 倍。展示了从 2nW 收集到的功率的自启动，对应于具有 100lx 照度的 0.8mm2 片上太阳能电池（即，相当于非常黑暗的阴天）。